Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.
Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.
You can learn more at our glossary entry.
Maximum effective ISO test data courtesy of DxO Mark.D5100 test data on DxO Mark 77D test data on DxO Mark
Side-mounted tilt / swivel LCD screen; same sensor and processing as the Nikon D7000; good speed and battery life; in-camera HDR and filter effects; Full HD video capture with aperture control; audio levels control and external microphone jack.
AF-S lens mount doesn't offer autofocus with screw-drive lenses; popup flash isn't the greatest; no built-in wireless flash control; HDR function doesn't microalign source images.
Very good image quality; Improved dynamic range at low ISOs; Very fast autofocus; Dual Pixel CMOS AF in Live View; Much improved RAW buffer depth; 1080/60p video; Quick Control Dial & top-panel LCD screen.
Default JPEGs slightly soft straight out of camera; Dynamic range & high ISOs lag behind competing cameras; No 4K video resolution.